Vehicle jack

ABSTRACT

A fluid operated lift jack for vehicles or the like having a first stop means for limiting downward movement of the jack cylinder and a second stop means for limiting upward movement of the cylinder, said stop means yieldably retained in operative position, a single control for selectively admitting or withdrawing fluid from the jack to raise or lower the cylinder, and said control having connection with said stop means to make the second stop means inoperative during raising and the first stop means inoperative during lowering of the cylinder.

Rishovd Mar. 7, R972 [54] VEHICLE JACK Primary Examiner-Othell M.Simpson [72] Inventor. Sigurd A. Rlshovd, Minneapolis, Mmn. Auomeycaflsen Came & sum" [73] Assignee: Royal industries, lnc., Osseo, Minn.22 Filed: Sept. 2, 1970 [571 [21 Appl No: 68,809 A fluid operated liftjack for vehicles or the like having a first stop means for limitingdownward movement of the jack cylinder and a second stop means forlimiting upward move- [52] U.S.Cl. ..254/2 B, 254/93 H "mm f thecylinder, said stop means yieldably retained in [5 1] int. Cl ..B60p1/00 operative position, a single comm for selectively admitting or [58]new 0! Search "254/2 2 2 93; 91/41 withdrawing fluid from the jack toraise or lower the cylinder,

91/45 and said control having connection with said stop means to makethe second stop means inoperative during raising and [56] Rate Cited thefirst stop means inoperative during lowering of the UNITED STATESPATENTS cylinder- 2,805,839 9/1957 Branick ..2S4/93 R 5 Cl 6 DrawingFigures i l K i in H PATENTEDHAR 11912 SHEET 1 [IF 2 8/61/20 19.zP/swarp ,"H Illh W W \mm VEHICLE JACK BACKGROUND OF THE INVENTION Thisinvention relates generally to fluid operated jacks for liftingvehicles, trailers, boats or the like and more particularly concernsstop mechanism in such jacks for locking the jack against accidental andrapid expansion or contraction.

Some vehicle jacks which are operated by hydraulic or pneumaticpressures are provided with a mechanical stop means such as a tooth andratchet to prohibit the jack from collapsing in the event of fluidleakage. Such a stop means is preferably operative during liftingmovement or extension of the jack.

However, it is also desirable to provide stop means to restrict upwardor explosive movement of the jack. This may occur when weight orpressure is suddenly removed from the jack such as when a vehicle slipsoff of it and the internal fluid pressure in the jack cylinder tends tocause it to extend.

For sake and convenience and clarity of understanding the stop meansprohibiting contraction or lowering of the jack will be referred to asthe down stop means while the stop means prohibiting extension orraising will be referred to as the up stop means.

In an ideal structure both stop means are operative when the jack is inneutral position, being neither extending or contracting, while only thedown stop means is operative as the jack is being extended and only theup stop means is effective as the jack is being contracted.

The invention is an improvement over US Pat. Nos. 2,805,839 and No.2,838,027 to Branick which are generally directed toward the sameobjectives The primary object of the present invention is to provide afluid operated jack for vehicles or the like with mechanical stop meansoperated by the fluid control means for limiting extension or retractionof the jack where leakages occur or where great pressures are suddenlyapplied to or removed from the jack.

Another object of the invention is to provide two independent stop meansin a jack for restricting expansion and contraction movement whereinboth stop means are normally spring held in locking engagement but whichmay be independently removed from locking engagement to permit extensionor retraction of the jack by fluid transfer.

Still another and more specific object of the invention is to provide afluid operated extensible and contractable jack with stop means forlimiting movement in either direction and wherein a single controloperates the fluid means and the stop means whereby one stop means isoperative when the jack is extended and the other stop means isoperative when the jack is contracted.

With these and other objects in view the invention broadly comprises anupright fluid extensible jack carrying a lifting device for engagementunder a vehicle frame, a valve device for selectively admitting ordraining fluid under pressure from the jack, a fixed support base forthe jack having an upright post with a series of oppositely directedrachet teeth at either side thereof, a pair of selectively operablelatch members respectively engageable with said ratchet teeth, and asingle manual control for simultaneously operating the valve device andlatch members.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a side elevation of the jack taken on line l-l of FIG. 2showing the jack in lowered or contracted condition with the upperportion thereof partially broken away to enable better understanding ofthe construction.

FIG. 2 is a front elevation of the jack in the same condition as shownin FIG. 1 with the lift arms broken away to conserve space.

FIG. 3 is an enlarged fragmentary vertical section through the centralportion of the jack taken on line 3--3 of FIG. 1 and DESCRIPTION OF THEPREFERRED EMBODIMENT Referring now more particularly to the drawings,reference numerals will be used to denote like parts or structuralfeatures in the different views. The jack is denoted generally by thenumber 10 and includes a base platform 11 supported on front and rearwheels denoted respectively at 12 and 14. An elongated tube 15 which issquare in cross section is mounted on the base platform in fixed uprightposition.

The sidewalls of tube 15, referred to as left and right sidewalls whenviewed in FIGS. 3 to 6, are respectively designated by numerals 16 and17. The left sidewall 16 has a row of tabs 18 punched inwardly therefromto project at an upwardly extending angle within the tube as shown inFIG. 3. These tabs have their curved upper edges punched out with eachleaving an arched downwardly facing stop edge 19 in wall 16. The rightsidewall 17 has a row of tabs 20 punched inwardly therefrom to projectat a downwardly extending angle within the tube. These tabs project injust the reverse direction from tabs 18 with the lower edges thereofpunched from wall 17 each leaving an arched upwardly facing stop edge21.

At its upper end the tube 15 is capped by a bearing member 24 having asealing ring 25 mounted peripherally thereon and a piston cup 26 mountedon the top thereof. The structure hereinabove described constitutes thebase or fixed portion of the jack.

The extensible portion of jack 10 is designated generally by the numeral30. This includes a cylinder member 31, closed at its upper end by plate32 and slidably encircling the bearing and piston members 24 and 26 andtube 15 to form an extensible jack assembly therewith. A U-shapedbracket 34 of channel material has its legs 35 welded to the sides ofthe cylinder 31 and extends downwardly therefrom on either side of thepost 15. The cross portion 36 of bracket 34 has an opening (not shown)through which post 15 extends.

A pair of plates 38 rigidly secured one to each bracket leg 35 extendrearwardly from the bracket in slightly diverging relation over baseplatform 11. Near their extended ends these plates jointly support anupwardly opening cross channel 39 within which aligned lift arms 40 havetheir inner ends pivoted on bolts 41 for movement between an extendedoperating position as in FIG. 2 and an upwardly folded nonoperatingposition. Saddle members 42 for engaging under an automobile frame orbumper bracket in lifting relation thereto, shown partially in FIG. 2,are mounted on each of the lift arms 40.

A valve 44 mounted on cylinder 31 is adapted for connection with astandard compressed airhose. Valve 44 connects the hose with a line 45which has an open connection with chamber 46 at the upper end ofcylinder 31 through coupling 47. A valve actuator 48 is pivoted at 49 onthe valve. When the actuator is in neutral position as shown in FIG. 2,the valve 44 is closed so that air can neither enter or leave thechamber 46. When the right side of the actuator 48 is tilted upwardly,as viewed in FIG. 2, air will be admitted into chamber 46 to raisecylinder 31 and extend the jack. Conversely, when the left side of theactuator is tilted upwardly, air is allowed to drain from chamber 46through the valve to atmosphere, thus lowering cylinder 31 andcontracting the jack.

Tilting of actuator 48 to operate valve 44 is accomplished by a controlrod 50. This rod is journaled for oscillating movement in verticallyspaced bearings 51 mounted on the cylinder 31 and has its upper end bentoutwardly to form an upper handle 52. The lower portion of the rod 50 isoffset inwardly as at 54 and then bent outwardly to form a bottom handle55.

The stop mechanism is designated generally by the numeral 57 and ismounted on the bracket 34. A pair of latch members 58 and 59 are mountedone in each of the bracket legs 35 in transversely opposing relation forsliding movement toward and away from each other on a common axis. Eachlatch member may have its inner end portion supported by the adjacentplate 38 through which it extends.

Each latch member carries a cross pin 61 and a spiral spring 62encircling the member and held under compression between the pin. A leg35 urges the latch member inwardly against the tube 15. Latch member 58has its inner end beveled as at 64 on its underside with the endpositioned to latch under the edges 19. Latch member 59 has its innerend beveled as at 65 on its upper side with the end positioned forlatching engagement over the edges 21.

A latch release strap 70 having a generally U-shape is mounted on thebracket 34 at the level of the latches. The strap has a pair of slots 71(FIG. 2) each of which receives a bolt 72 allowing the strap lateralsliding movement. The end portions of the strap extend rearwardly alongthe sides of bracket 34 and are slotted as at 74 (FIG. 1) to receive theouter ends of the latches S8 and 59. Cross pins 75 are provided in thelatches outside of the strap. A bearing ring 76 is mounted medially onthe strap and the offset portion 54 of rod 50 extends therethrough.

In operation the jack or lift is wheeled into the proper liftingposition relative to the front or rear end of a vehicle by means ofhandles 78 mounted near the top of the cylinder. The jack is positionedso that the saddle members 42 will engage under transversely spacedportions of the vehicle frame when the jack is extended.

An air pressure hose is then attached to valve 44. Handle 52 (or handle55) is then turned to the right as viewed in FIG. 2 tilting the rightside of actuator 48 upwardly and causing valve 44 to admit air throughline 45 to chamber 46. This causes the entire extensible portion 30 ofthe jack to raise including the plates 38 and lift arms 40 raising thevehicle to the desired position.

As the handle 52 is turned to the right rod 50 will turn in bearings 51causing the rearwardly offset portion 54 of the rod to shift to the leftmoving strap 70 therewith to the position shown in FIG. 5. Accordingly,latch member 58 is removed from engagement with post 15. As the jackextends the bracket 34 carries latch member 59 upwardly along the wall17 with the beveled surface 65 thereof sliding along the tabs 20. In theevent that any leakage should occur in the air pressure system, latch 59will provide a stop against the adjacent stop edge 2 ll preventingcollapsing of the jack.

When the jack has been extended to the desired position handle 52 isreturned to its centered position moving the stop mechanism to itsneutral position shown in FIG. 4 bringing latch 58 again into engagementwith the stop edges 19 on wall 16 and the extensible portion 30 of thejack is locked against movement in either direction.

To contract the jack the handle 52 is again turned to the right so as toextend the jack slightly so that both latches 58 and 59 are disengagedfrom edges 19 and 21. The handle is then turned to the left as viewed inFIG. 2 tilting the left side of actuator 48 upwardly. This adjusts valve44 to open chamber 46 to atmosphere through line 45. With this movementof rod 50 the stop mechanism 57 is shifted to the position shown in FIG.6 withdrawing latch 59 from engagement with the wall 17 but leavinglatch 58 in ratcheting engagement with tabs 18 in wall 16. Accordingly,if weight is suddenly removed from lifting arms 40, the latch 58 willengage against the stop edge 19 immediately thereabove preventing rapidexploding or extension of the jack.

The invention thus provides a construction wherein a single controloperates the jack and the stop mechanism 57 so that positive safetylocking action is automatically provided during either extension orcontraction.

Having now therefore fully illustrated and described my invention, whatI claim to be new and desire to protect by United States LettersPatentjs:

1 In a vehicle ack having a base, a fluid actuated lift member mountedon the base for raising and lowering movement, a fluid cylinderassociated with the lift member, valve means for admitting fluid to anddischarging it from the cylinder, an upright member on the base havingone row of upwardly directed stop teeth and a second row of downwardlydirected stop teeth, first and second latch members mounted on the liftmember and in yieldable engagement respectively with said first andsecond rows of teeth to lock the member against raising and loweringmovement, a single control means movable to one position forsimultaneously admitting fluid to the cylinder to raise the lift memberand to make said second latch member inoperative and to a secondposition for simultaneously discharging fluid from the cylinder to lowerthe lift member and to make said first latch member inoperative.

2. The subject matter of claim 1 wherein said latch members are disposedin opposing horizontal alignment on the lift member, said valve meansbeing mounted on the lift member in spaced relation above the latchmembers, and said control means comprising an elongated rod joumaled invertical position on the lift member for oscillating movement with theupper portion of the rod having operative connection with the valvemeans and the lower portion of the rod having operative connection withthe latch members.

3. The subject matter of claim 2 wherein said rod has radially extendinghandles for oscillating the rod at both its upper and its lower ends.

4. In a fluid operated lift jack for vehicles or the like,

a. a support base,

b. an elongated tube mounted integrally in upright position on the baseand having a piston head on its upper end,

c. a lift cylinder having a closed upper end mounted on the piston forvertical sliding movement axially of the tube and having a vehiclelifting bracket thereon,

d. means for admitting air under pressure to and discharging it from thelift cylinder above the piston for selectively raising or lowering thecylinder,

e. means forming rows of ratchet teeth on opposing sides of the tube,

. a pair of opposing latch members supported by the cylinder in positionto be engageable one with each row of ratchet teeth,

g. a single control for the air means and the latch members adapted tomove one latch member to a nonoperative position when air is admitted tothe cylinder and to move the other latch member to a nonoperativeposition when air is discharged from the cylinder.

5. The subject matter of claim 4 wherein h. each of said latch membersis provided with a spring means urging it inwardly into engagement withthe ratchet teeth,

i. a bracket member mounted on the cylinder for lateral shiftingmovement and having connection with each of said latch members,

j. and said control comprising an upright rod journaled on the liftcylinder and connected to the bracket member at a point offset from itsturning axis whereby as the rod is rotated in one direction it willshift the bracket in one direction to move one latch member outwardlyagainst its spring means and when rotated in the opposite direction willmove the other latch member outwardly against its spring means.

1. In a vehicle jack having a base, a fluid actuated lift member mountedon the base for raising and lowering movement, a fluid cylinderassociated with the lift member, valve means for admitting fluid to anddischarging it from the cylinder, an upright member on the base havingone row of upwardly directed stop teeth and a second row of downwardlydirected stop teeth, first and second latch members mounted on the liftmember and in yieldable engagement respectively with said first andsecond rows of teeth to lock the member against raising and loweringmovement, a single control means movable to one position forsimultaneously admitting fluid to the cylinder to raise the lift memberand to make said second latch member inoperative and to a secondposition for simultaneously discharging fluid from the cylinder to lowerthe lift member and to make said first latch member inoperative.
 2. Thesubject matter of claim 1 wherein said latch members are disposed inopposing horizontal alignment on the lift member, said valve means beingmounted on the lift member in spaced relation above the latch members,and said control means comprising an elongated rod journaled in verticalposition on the lift member for oscillating movement with the upperportion of the rod having operative connection with the valve means andthe lower portion of the rod having operative connection with the latchmembers.
 3. The subject matter of claim 2 wherein said rod has radiallyextending handles for oscillating the rod at both its upper and itslower ends.
 4. In a fluid operated lift jack for vehicles or the like,a. a support base, b. an elongated tube mounted integrally in uprightposition on the base and having a piston head on its upper end, c. alift cylinder having a closed upper end mounted on the piston forvertical sliding movement axially of the tube and having a vehiclelifting bracket thereon, d. means for admitting air under pressure toand discharging it from the lift cylinder above the piston forselectively raising or lowering the cylinder, e. means forming rows ofratchet teeth on opposing sides of the tube, f. a pair of opposing latchmembers supported by the cylinder in position to be engageable one witheach row of ratchet teeth, g. a single control for the air means and thelatch members adapted to move one latch member to a nonoperativeposition when air is admitted to the cylinder and to move the otherlatch member to a nonoperative position when air is discharged from thecylinder.
 5. The subject matter of claim 4 wherein h. each of said latchmembers is provided with a spring means urging it inwardly intoengagement with the ratchet teeth, i. a bracket member mounted on thecylinder for lateral shifting movement and having connection with eachof said latch members, j. and said control comprising an upright rodjournaled on the lift cylinder and connecTed to the bracket member at apoint offset from its turning axis whereby as the rod is rotated in onedirection it will shift the bracket in one direction to move one latchmember outwardly against its spring means and when rotated in theopposite direction will move the other latch member outwardly againstits spring means.